In current purely electrically driven automobiles and hybrid automobiles, the dynamic characteristics of electric motors cannot meet the requirements of entire vehicles, therefore the startup acceleration performances of the entire vehicle of purely front-driven or rear-driven new energy automobiles are relatively insufficient.
Furthermore, presently, the speed reducers of purely electrically driven or hybrid new energy automobiles cannot use conventional friction clutches because of the large shock on the rotor shaft of electric motor. Therefore, conventional speed reducers carried by electric motors can only adopt hard connection mode, and such clutches have neither of clutching function, cushioning function and self-aligning function, and the requirements of new energy automobiles cannot be satisfied. In addition, as the power system of the entire vehicle does not have clutching function, the startup and stop of the entire vehicle can only rely on the startup and stop of the electric motor, which affects the startup and stop response time of the entire vehicle.